Photo-resist etching may be used to create micro-structures in micro-electronic devices. For example, photo-resist etching is used to create micro-fluidic chambers, including ink manifolds and firing chambers, in a barrier layer of a fluid ejector such as an ink-jet print head. Photo-resist etching is used to form nozzles or fluid-transfer bores in an orifice layer arranged above the barrier layer of an ink-jet print head.